<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <div>
        <input type="button" value="点我" onclick="display(10)">
    </div>
    <script>
        let a = 1

        function display(num) {
            a += num
            console.log("我叫杨旭", a)
        }

        function sum(a, b) {
            return a + b
        }

        let result = sum(100, 300)
        console.log(result)

        // let 函数名 = (接收的参数) => {要执行的代码块}
        let sum2 = (a, b) => {
            return a + b
        }
        let res2 = sum2(1,2)
        console.log(res2)
    </script>
</head>
<body>

</body>
</html>